twi_nonblock.h

/*
 * twi_nonblock.h
 *
 * Copyright 2012 Marije Baalman.
 *
 */

#ifndef TWI_NONBLOCK_H_
#define TWI_NONBLOCK_H_

#include <hardware_defines.h>
// Added by TB2014 for Teensy 3 port
#if IS_AVR() // this code is only for AVRs

#include "Arduino.h"
#include <compat/twi.h>

#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

// --- twi reading variables
  #ifndef TWI_FREQ
  #define TWI_FREQ 100000L
  #endif

  #ifndef TWI_BUFFER_LENGTH
  #define TWI_BUFFER_LENGTH 32
  #endif

  #define TWI_READY 0
  #define TWI_PRE_MRX   1
  #define TWI_MRX   2
  #define TWI_PRE_MTX   3
  #define TWI_MTX   4
  #define TWI_SRX   5
  #define TWI_STX   6

static volatile uint8_t twi_state;
static volatile uint8_t twi_oldstate;
// static uint8_t twiint_masrw;
static uint8_t twi_slarw;

static uint8_t twi_masterBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_masterBufferIndex;
static uint8_t twi_masterBufferLength;

static volatile uint8_t twi_error;

#define BUFFER_LENGTH 32
static uint8_t rxBuffer[BUFFER_LENGTH];
static uint8_t rxBufferIndex = 0;
static uint8_t rxBufferLength = 0;

static uint8_t txAddress = 0;
static uint8_t txBuffer[BUFFER_LENGTH];
static uint8_t txBufferIndex = 0;
static uint8_t txBufferLength = 0;

static uint8_t transmitting;


void initialize_twi_nonblock();

uint8_t twowire_requestFrom(uint8_t address, uint8_t quantity);
void twowire_beginTransmission( uint8_t address );
void twowire_send( uint8_t data );
uint8_t twowire_endTransmission(void);

/// non-blocking functions:
uint8_t twi_initiateReadFrom(uint8_t address, uint8_t length);
void twi_continueReadFrom();

uint8_t twi_readMasterBuffer( uint8_t* data, uint8_t length );

uint8_t twi_initiateWriteTo(uint8_t address, uint8_t* data, uint8_t length );
void twi_continueWriteTo();


void twi_reply(uint8_t ack);
void twi_stop(void);
void twi_releaseBus(void);

/// blocking versions:
uint8_t twi_readFromBlocking(uint8_t address, uint8_t* data, uint8_t length);
uint8_t twi_writeToBlocking(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait);

#endif
#endif